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Casio TM-100 Transmitter Watch

In 1987, Casio released the TM-100, a most unusual digital watch. On the surface, it appears to be a normal time-telling model but deep inside Casio embedded circuitry to transmit audio signals. Flip the little lever above the display, raise the telescopic antenna and speak or play music into the little microphone and the TM-100 will broadcast the audio to nearby radios! A tiny tuning knob allows you to calibrate the preferred frequency on the FM band (specifically, the Japanese FM band which is 76-90MHz and a portion of the US FM band, 87.5-108MHz). The case is all plastic and it requires two batteries, one for the timekeeping feature and one for the transmitter.

To us, the TM-100 is partially shrouded in mystery. We have never seen it advertised and it is a relatively uncommon watch. The transmitter feature was never included in any other model. We know of a few gadgets sold in Japan (the birthplace of karaoke!) included a transmitter but no wristwatch. Does anyone have any information?

Our friend akitaishi posted a couple of very cool videos of his Casio TM-100 in action! Witness a most interesting marriage of technologies: the source is an iPod with digital audio files, playing into the Casio TM-100 and broadcast over FM into a classic ’80s boombox.

19 thoughts on “Casio TM-100 Transmitter Watch”

To us, the TM-100 is partially shrouded in mystery. We have never seen it advertised and it is a relatively uncommon watch. The transmitter feature was never included in any other model. We know of a few gadgets sold in Japan (the birthplace of karaoke!) included a transmitter but no wristwatch. Does anyone have any information?

These are fantastic timepieces that offer wireless RF transmission of voice and music signals to radio waves over the FM radio band. A little ahead of their time when they were produced and thus under appreciated. Having a keen interest in these watches when I first knew about them, I went on over 3 long years to acquire 2 working samples. I am the originator of 2 experiments to show how both TM-100 are able to transmit radio wave signals over to boomboxes; serving as a wireless broadcasting medium. The above clips are my demonstrations of the Casio TM-100 in action and glad that the community has enjoyed the demos. Please like the You-tube clips, share them on social media so that more people get to know about these great Casio pieces. Thank you.

Being that this transmitter uses a tuning knob it will drift so bad it isn’t funny. I’m sure its why it was a flop. What they should have done was use a crystal or PLL tuner. It would be nice say if you needed to shop at a store that you didn’t know very well while you travel. You would then transmit a signal so your driver could find you. They drive towards the signal and Oh there you are. 87.7 or 87.9 Mhz would be perfect for that.

my Hitachi TRK-9100W is malfunctioning, it volumes up and drastically goes low automatically, the repair was beyond my control so I decided to bring my patient to a trusted technician, yet, bad news came too. It appears that the MIXER HAS ISSUES ON THE FIRST I.F. then the RESISTORS AND CAPACITORS AROUND IT HAD RUSTED.

Now, I am here for requesting help to those people that has A CIRCUIT DIAGRAM OF HITACHI TRK-9100W OR PLEASE KINDLY TAKE A PICTURE OF YOUR OWN HITACHI TRK-9100W MIXER PART AND KINDLY PLEASE POST IT HERE OR ATTACH IT ON MY MAIL. yatcojeffrey@yahoo.com

All those who will help are very much welcome! Thank you in advance!

P.S. Who would like to see this baby go to the Graveyard, I think no one does.